LONDON -- Sony's PSP (PlayStation Portable) will benefit from the addition of wireless broadband functions, following a deal Sony has signed with BT.

Over the course of the four-year contract, the companies will develop features to enable high-quality handheld video calls, voice calls, and messaging to be carried out on the device.

BT will deliver the service initially in the UK. The partnership will integrate PSP with the BT Broadband video and voice 'softphone' products that are already available. Additional features will be added later to allow calls to be made and messages sent to PCs, landlines and mobiles.